III Iodide

Submitted by N. W. Gregory and Lyman L. Handy Checked by S. Young Tyree, jR.f 

Pure chromium(III) iodide can be prepared by the direct reaction of powdered chromium metal with iodine.1 The procedure given here can be used conveniently to prepare quantities up to 25 g. 

A reaction vessel is constructed of 28-mm.-o.d. pyrex tubing as shown in Fig. 13. This is attached through a 

Iodine is determined by igniting a sample in air with the full flame of a Bunsen burner and comparing the weight of the chromium(III) oxide produced with the initial weight of the sample. Chromium is determined in the usual manner by fusing the oxide with sodium peroxide and measuring the quantity of chromate ion produced. Anal. Calcd. for Crl3 Cr, 12.02 I, 87.98. Found Cr, 12.03, 11.73 I, 85.47, 87.65. 

Chromium(III) iodide is a black, crystalline compound, isomorphous with chromium(III) chloride. When pure, 

Submitted by J. P. KOPASZ, R. B. HALLOCK, and O. T. BEACHLEY, Jr. Checked by W. RODGER NUTTt 

Indium(III) iodide is an important starting material for the preparation of a great variety of organoindium compounds. The synthesis described herein is a modification of a published procedure. Since the title compound is hygroscopic, a combination of Schlenk and high vacuum techniques is employed.  

00-g (52.3-mmol) sample of indium foil cut into small strips and 20.0 g (78.8 mmol) of iodine are placed in a 250-mL flask equipped with a magnetic 

Indium(III) iodide is a yellow hygroscopic crystalline solid, mp 210°. The compound exists in the solid state as iodine bridged dimers (I2lnl2lnl2) and is readily soluble in organic solvents such as benzene, chloroform, and diethyl ether. The vibrational spectrum has been reported, but the observed infrared and Raman frequencies occur in the far-infrared region, below 250 cm .  

Shriver, The Manipulation of Air-Sensitive Compounds. McGraw-Hill, New York, 1969. 

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Iron(III) chloride forms numerous addition compounds, especially with organic molecules which contain donor atoms, for example ethers, alcohols, aldehydes, ketones and amines. Anhydrous iron(III) chloride is soluble in, for example, ether, and can be extracted into this solvent from water the extraction is more effective in presence of chloride ion. Of other iron(III) halides, iron(III) bromide and iron(III) iodide decompose rather readily into the +2 halide and halogen. 

The chemistry of the bromides is completely analogous to that of the chlorides. Gold(III) iodide [31032-13-0] on the other hand, is unstable, loses iodine, and converts to Aul [10294-31-2] (176). 

Iron(III) iodide [15600-49-4], Fefy, is prepared by the oxidative photodecarbonylation of diiodotetracarbonylkon(II) ki the presence of dkodine (7). The black soHd obtained is extremely hygroscopic, spariagly soluble only ki dichloromethane, and decomposes to kon(II) iodide and dkodine when exposed to donor solvents such as tetrahydrofuran, acetonitrile, water, or pyridine. It also decomposes when exposed to light. 

Antimony(III) iodide [7790-44-5] Sbl, forms red rhombohedral crystals, intermediate in stmcture between a molecular and an ionic crystal. In Sbl vapor there is no indication of association. 

Arsenic tniodide (arsenic(III) iodide), Asl, can be precipitated from a hot solution of trivalent arsenic in hydrochloric acid by the addition of potassium iodide, or it can be formed by treating elemental arsenic with a solution of iodine in carbon disulfide. It is not as easily hydrolyzed as the other arsenic haUdes, but it decomposes slowly in air at 100 °C (rapidly at 200°C) to give a mixture of iodine, arsenic trioxide, and elemental arsenic. Solutions of Asl are unstable, particularly in the presence of moisture. 

All the anhydrous - -3 and +2 halides of iron are readily obtained, except for iron(III) iodide, where the oxidizing properties of Fe and the reducing properties of 1 lead to thermodynamic instability. It has, however, been prepared in mg quantities by the following reaction, with air and moisture rigorously excluded,... 

Aqueous solutions of dimetiiylgold(III) nitrate easily react with pyrazole and 3,5-dimethylpyrazole to form the pyrazolate complexes 271 (R = H, Me) [85 JOM (295)401]. However, 3,5-diphenylpyrazole gives the complex [Me2Au(3,5-Ph2pzH)2], where the ligand is not deprotonated. To obtain the 3,5-diphenylpyra-zolate complex, dimethylgold(III) iodide must be reacted with silver diphenylpyra-zolate. 

Eisen-hydrozyd, n. ferric hydroxide, iron(III) hydroxide, -hydroxydul, n. ferrous hydroxide, iron(II) hydroxide. -jodid,n. iron iodide, specif, ferric iodide, iron(III) iodide, -jodiir, n. ferrous iodide, iron(II) iodide, -jodiirjo-did, n. ferrosoferric iodide, iron(II,IIl) iodide, kalium, n. potassium ferrate, -kaliumalaun,... 

Gold-hydroxyd, n. gold hydroxide, specif, auric hydroxide, gold(III) hydroxide, -jodid, n. gold iodide, specif, auric iodide, gold(III) iodide, -jodiir, n. aurous iodide, gold (I) iodide, -kafer, m. gold beetle. 

When the two elements antimony and iodine are heated in contact with one another (Figure 3.5), they react to form antimony(III) iodide. 

Gold(III) iodide has not been definitely characterized in the solid state substances with this formula in the solid state are probably gold(I) polyiodides Au+If AuI3 has also been detected in the gas phase (mass spectra). 

E.22 (a) How many CaH2 formula units are present in 5.294 g of CaH2 (b) Determine the mass of 6.25 X 1024 formula units of NaBF4, sodium tetrafluoroborate. (c) Calculate the amount (in moles) of 9.54 X 1021 formula units of Cel3, cerium(III) iodide, a bright yellow, water-soluble solid. 

The key intermediate for the antibacterial agent levofloxcin, (,S>( )-7,8-difluoro-2,3-dihydro-3-methyl-4H-l,4-benzoxazin, was prepared by the asymmetric hydrogenation of (442) by the catalyst system made in situ from [Ir(cod)Cl]2, biphosphine and bismuth(III) iodide.703 The product was isolated in 96% yield, with an enantiomeric purity of 90% for the biphosphine (2S,45)-BPPM,(2S,45)-N-( -butoxy-carbonyl)-4-(diphcnylphosphino)-2-[(diphcnylphosphino)mcthyl]-pyrrolidine. 

The reactions in Equations (5) and (6) involve oxidation of rhodium(I) to rhodium(III). Equations (6) can also be written as an oxidative addition of I2 (formed thermally from 2 HI) to (1). Rhodium(III) iodides may precipitate from the reaction medium. They have to be converted to rhodium(I) again by water and carbon monoxide. 

Titanium (IV) iodide may be prepared by a variety of methods. High-temperature methods include reaction of titanium metal with iodine vapor,1-3 titanium carbide with iodine,4 titanium(IV) oxide with aluminum (III) iodide,5 and titanium (IV) chloride with a mixture of hydrogen and iodine. At lower temperatures, titanium (IV) iodide has been obtained by the combination of titanium and iodine in refluxing carbon tetrachloride7 and in hot benzene or carbon disulfide 8 a titanium-aluminum alloy may be used in place of titanium metal.9 It has been reported that iodine combines directly with titanium at room temperature if the metal is prepared by sodium reduction of titanium (IV) chloride and is heated to a high temperature before iodine is... 

A solution of iron(III) iodide is added to a solution of ammonium thiocyanate ... 

Chromium(II) iodide, 6 531 Chromium(III) iodide, 6 532 Chromium(IV) iodide, 6 535 Chromium—iron alloys, 23 300... 

Iron(II) formate dihydrate, 14 537 Iron(II) fumarate, 14 537 Iron gelbs, 19 399, 400 Irondl) gluconate dihydrate, 14 541 Iron group carbides, 4 690-692 Iron halides, 14 537-540 Iron hydroxide, water exchange rates and activation parameters of hexaaqua complexes, 7 589t Iron(II) hydroxide, 14 542 Iron(III) hydroxide, 14 542 Iron hydroxides, 14 541—542 Iron(II) iodide, 14 540 Iron(III) iodide, 14 540 Iron/iron alloy plating, 9 813—814. See also Fe entries... 

Procedure 1 Synthesis of the Amine Racemization Catalyst Pentamethylcyclopentadienyliridium(III) Iodide Dimer... 

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